The Naval Oil Reserve became the National Petroleum Reserve, Alaska. I was on the early design team for what was to be the first production site drill site, CD5 for ConocoPhillips, an expansion of the Alpine Central Production facility back in 2005.
Because of that experience, I've followed it rather closely, even getting to review some logs from a few exploratory drilling. I've never seen any claim of a Prudhoe size field. Sorry but I have to doubt that claim.
What has been found has been extremely light and high in value, but nothing massive in size. The CD5 drill site has been held up with various permitting issues, mostly around the bridge over the Nigliq Channel of the Colville River Delta. We had a FR thread about that last week:
North Star is also offshore, but they are drilling what in the gulf would amount to bay or near shore rigs. The deeper areas are not in production.
ANWR was set up as an oil drilling area, but they have never allowed production.